Their most grown-up move, however, is to restructure their business, new millennium-style. Boyz II Men's latest project, Twenty, released Tuesday, is a product of their own label, MSM (Morris, Stockman, Morris). The two CDS are a compilation of classic hits, such as "End of the Road" and "I'll Make Love To You," plus 12 new songs, including the group's latest single, "More Than You'll Ever Know," a duo with the industry's best comeback, Gap Band lead singer Charlie Wilson.
Boyz II Men owns the rights to all of the new music, so after they pay for marketing and CD manufacture, they stand to make a pretty penny on this 10th album.
"We've made money, but we've never been able to possibly make this much," said Stockman, the group's tenor and a judge on NBC's a cappella reality show, The Sing-Off. "If all goes well," he said, "it could be a very good year."
Financially speaking, maybe - but it's a long shot that Boyz II Men will match their early 1990s peak (four Grammys and 60 million albums sold worldwide). They remain one of the best-selling R&B groups in history - the best, they claim.
"They were an amazing group," said Patty Jackson of Philadelphia's WDAS-FM (103.5), one of the first disc jockeys to interview the group back in the 1990s. "They were creative, and they brought a new sound that really blended the old sound of Philadelphia with the new sounds of the time. They were just so talented."
"More Than You'll Ever Know" has sold more than 15,000 copies, according to Nielsen SoundScan.
"Boyz II Men are in an interesting place," said James Peterson, director of Africana studies and a hip-hop scholar at Lehigh University. Peterson credits Boyz II Men with bringing a new element of soul unseen before in hip-hop music.
"They are not old enough to command the respect of, say, a Four Tops, but they don't have the same relevance of a Trey Songz, either. It will be interesting to see what comes next for them."
Stockman and the two Morrises are all in their late 30s, and all have children. The Morrises live in the Philly area, while Stockman lives in California, partly to be close to the show and partly to work on a few television film collaborations he has in the pipeline.
The group still perform old standards together. They also do casinos, and in September previewed some of their new music at the Liacouras Center. Like many acts from their generation, they take part in old-school concerts. But their real bread and butter comes from performances in Europe.
"Europe is the reason we can still feed our families," Stockman said. "It's their mentality: When they love you over there, they love you forever. The United States is a little bit more fickle."
Each member talked recently, with a quiet confidence that's a bit boastful, of their superstar past, but all were tentative about where they fit into the music industry now.
The truth is, where they fit has always been in the middle. As the direct descendants of New Edition (Boyz II Men were discovered by NE member Michael Bivins), they are poster children for Gen Xers. Stockman calls them a conduit between the old school and the new.
Among the first to blend hip-hop and gentler R&B, they are among the last of the boy bands who can get down with the doo-wop street-corner music of the Motown era. They ushered in the late-'90s wave of male bands such as Troop and Az Yet, as well as sexier reincarnations of themselves such as Jodeci and Silk. So, if Boyz II Men were such trailblazers, why are people so quick to label them irrelevant today?
"That's just a little disrespectful," Stockman said. "Why are we over? Who gave anybody the power to write that decree?"
Egos aside, the group say they are moving forward. Boyz II Men recently completed a Christmas song with Justin Bieber. Titled "Falalalala," it appears on Bieber's Under the Mistletoe CD, on sale Tuesday.
"That little dude is the truth," Wanya Morris chuckled.
But Bieber is the only of-the-moment artist they've collaborated with.
"To be honest, a lot of younger artists didn't think Boyz II Men were relevant," Nathan Morris said a little more than a week ago, still groggy from standing in line all night to get the latest iPhone. He is the Boyz II Men member who worked most closely on the Boyz II Men app.
"Hot artists want to work with hot artists," he said.
So, apart from their tunes with Wilson and Bieber, Boyz II Men keep the act among themselves.
For old times' sake, in making Twenty they brought in producer faves of their target audience of tastemakers-turned-parents-of-tweens - Kenneth "Babyface" Edmunds and new jack swing king Teddy Riley - for an album reminiscent of II.
The tunes are definitely on the softer side, but Boyz II Men fans won't be disappointed. Tracks such as "So Amazing" embody the passion Wanya Morris is known for, and "I Shoulda Lied" will remind listeners of "Water Runs Dry."
"We wanted to be believable," said Wanya Morris. "You don't want someone to fall in love with music and realize it is a lie. We wanted to maintain the integrity of the band, and we sing about love."
Stockman later added: "Can you imagine Boyz II Men putting out a song with Lil Wayne? That would be funny. We know to stay in our lane."
Contact staff writer Elizabeth Wellington at 215-854-2704, firstname.lastname@example.org, or @ewellingtonphl on Twitter.